Risk Factors for the Development of Neurological Deficits in Metastatic Spinal Disease: An International, Multicenter Delphi Study.

Study Design: Delphi study.

Objective: The objective of this study was to identify risk factors associated with the development and/or progression of neurological deficits in patients with metastatic spinal disease.

Methods: A three-round Delphi study was conducted between January-May 2023 including AO Spine members, comprising mainly neurosurgeons and orthopedic surgeons. In round 1, participants listed radiological factors, patient characteristics, tumor characteristics, previous cancer-related treatment factors and additional factors. In round 2, participants ranked the factors on importance per category and selected a top 9 from all factors. Kendall's W coefficient of concordance was calculated as a measure of consensus. In the final round, participants provided feedback on the rankings resulting from round 2. Lastly, the highest-ranking factors were more clearly defined and operationalized by an expert panel.

Results: Over two hundred physicians and researchers participated in each round. The factors listed in the first round were collapsed into 12 radiological factors, 14 patient characteristics, 6 tumor characteristics and 12 previous cancer-related treatment factors. High agreement was found in round 3 on the top-half lists in each category and the overall top 9, originating from round 2. Kendall's W indicated strong agreement between the participants. 'Epidural spinal cord compression', 'aggressive tumor behavior' and 'mechanical instability' were deemed most influential for the development of neurological deficits.

Conclusion: This study provides factors that may be related to the development and/or progression of neurological deficits in patients with metastatic spinal disease. This list can serve as a basis for future directions in prognostication research.